This Phase I SBIR proposal is the first step in the development of inhalable IgG microparticles for immunoprophylaxis against Influenza A, a category C Priority Pathogen. In Phase I, Aktiv-Dry will simultaneously stabilize, dry, and micronize IgG antibody solutions by a newly patented process, Carbon Dioxide Assisted Nebulization with a Bubble Dryer(R) (CAN-BD). The best operating parameters for the synthesis and coating of particles 0.5 to 5 microns in diameter will be determined and the size distribution, characteristics and antigen binding activity of stabilized IgG particles will be measured by in vitro tests. Release rates of coated IgG particles will be measured in an effort to enhance the Phase II in vivo tests of the administration of micronized IgG to the lungs of mice challenged with influenza A. The goals are to increase storage stability, and efficacy of treatment of influenza with single dose dry powder inhalers containing IgG. Development of stable antibody powders with high surface areas that can be stored for months at room temperature in the field without refrigeration and can rapidly redissolve in active form is an added benefit for IgG delivered by conventional injection. Aktiv-Dry LLC was formed by Prof. Sievers and Prof. Carpenter to develop and carry into the market inventions made at the University of Colorado Center for Pharmaceutical Biotechnology.